Azo dye and process of making same.



UNITED STATES PATENT OFFICE.

MELCHIOR BDNI GER, OF BASEL, SWITZERLAND, ASSIGNOR TO CORPO- RATION OF CHEMICAL W'ORKS FORMERLY SANDOZ, OF BASEL,

SWITZERLAND.

Specification of Letters Patent.

Patented Jan. 15, 1907.

Application filed April 12. 1906- Serial No. 311,263.

To all whom it mag concern.-

Be it known that I, lViELOHIOR BoNIeER, doctor of philosophy, chemist, and a resident of Fabrikstrasse, Basel, Switzerland, have invented new and useful Improvements in the Manufacture of New Monoazo Dyes, of which the following is a specification.

This invention relates to the manufacture of new monoazo dyes suitable for subsequent chroming or treatment with bluestone by the action of orthodiazophenol compounds on aryl 1.8 naphthylamin sulfonic acids. The direct dyeings of these dyestuffs on wool in an acid-bath vary from blue-red to dark violet and are transformed by subsequent treatment with bichromate or blue-stone into very valuable dark blue, blue-black, and deep-black shades of excellent fastness to light and milling. The best results have been obtained by employing for the combination with aryl 1.8 naphthylamin sulfonic acids the diazo compounds of monoand dichloro-ortho-amidophenol, monoand dinitro-orthoamidophenols, chloro-nitroor tho-amidophenols, nitro ortho amido cresols, ortho-amidophenol sulfonic acids, their homologues and substitution products.

The following examples will serve to illustrate this invention and how it may be performed. The parts are by weight:

First. Dissolve 15.4 parts of paranitroorthoamidophenol in two hundred parts of water and twelve parts of hydrochloric acid of 21 Baum and diazotize this solution after cooling to 0 centigrade by addition of seven parts of sodium nitrite. Introduce the diazo compound thus obtained inform of a yellowish crystalline powder into a neutral solution of thirty-four parts phenyl-1.8 naphthylamin sulfonate of soda in four hundred parts of water. After stirring for about forty-eight hours the reaction is complete, six parts of Solvay soda being then added and the dyestufl precipitated with common salt, filtered OE, and dried. It dissolves in water and ethylic alcohol with Bordeaux-red color, in strong sulfuric acid with dark-violet color. 011 addition of acids to the aqueous solution the dyestufi is precipitated in violet-blue flakes. It dyes wool brown-violet in an acidbath. By subsequent chroming a very valuable black with blue reflection and of excellent fastness to light, acids, alkalies, and milling is obtained.

Second. The diazo compound from 22.5 parts of 4-chloro-2 amidophenol 6 sulfonic acid, reacting but slightly acid on Congo paper, is mixed with the solution of thirty-six parts of paratolyl 1.8naphthy1amin sulfonate of soda in four hundred parts of water. The reaction being complete after twentyfour hours stirring at ordinary temperature, six parts of Solvay soda are then added, whereupon the dyestufi is precipitated from the blue-red solution by common salt. It dyes wool direct from acid-baths in Bordeaux-red shades, which turn violet-blue 011 subsequent treatment with blue-stone and dark blue on subsequent treatment with bichromate. A similar dyestuff is obtained in using in the foregoing process the diazo compound of orthoamidoparacresol sulfonic acid.

The combination of all the different orthodiazophenol compounds with the aryl-1.8 naphthylamin sulfonic acids may be carried out in an analogous manner. Also sodium acetate or sodium bicarbonate or other salts having a weak alkaline reaction may be added to accelerate the copulation of the diaZo body, or the dyestuff-sulfonic acid formed during the reaction may be gradually neutralized by alkalies in order to complete the reaction. The process, therefore, is not confined to the details of the specific foregoing examples.

The new orthohydroxyazo dyestuffs in the form of their sodium salts are dark powders of metallic luster dissolving in water and ethylic alcohol with blue-red to violet, in strong sulfuric acid with violet to blue color, depositing therefrom on dilution with water the dyestuff in form of violet to blue flakes. Upon reductionas, for instance, with stannous chlorid and hydrochloric acidthey are split off in the corresponding orthoamidophenol compounds and aryl 1.4 naphthylenediamin 8 sulfonic acid. They dye unmordanted wool from an acid-bath in blue-red to violet shades, which turn into dark blue to black by subsequent chroming or treatment with blue-stone.

Now what I claim, and desire to secure by Letters Patent, is the following:

1. The herein-described process for the manufacture of monoazo dyes by combining orthodiazophenol compounds with aryl-1.8 naphthylamin sulfonic acids, substantially as described.

with blue-stone; yielding upon reduction an orthoamidphenol compound and an aryl-1.4 naphthylenediamin 8 sulfonic'acid, substantially as hereinbefore described.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two witnesses, this 29th day of March, 1906.

MELOHIOR BONIGER.

Witnesses GEO. GIFFoRD, WILHELM Bi'JNz. 

